Which factor could lead to inaccurate measurement of arterial blood gases?

Delayed analysis of arterial blood gas samples can lead to inaccurate results due to the metabolic processes that continue in the blood after it is withdrawn. When a sample is not analyzed promptly, several changes can occur, including alterations in pH, partial pressures of gases like oxygen and carbon dioxide, and levels of bicarbonate. For instance, if the sample sits too long at room temperature, the metabolic activity may deplete oxygen levels and increase carbon dioxide levels due to cellular metabolism, resulting in an inaccurate representation of the patient’s current gas exchange status.

In contrast, using an unsterilized syringe may raise the risk of contamination, which could potentially affect the results, but it does not directly cause changes in the biochemical parameters of the blood gas. Mixing the sample with saline would dilute the sample, which could lead to altered measurements, but it doesn’t occur through the natural processes of the blood. Proper sealing of the syringe is essential for maintaining sample integrity, but does not contribute to inaccuracies if the sample is analyzed in a timely manner. Therefore, the critical factor affecting accuracy in this scenario is the delay in the analysis of the sample, resulting in skewed measurements.